Login via Face Detection
FOR GDM GDM LOGIN MANAGER
Add the PPA repository and Update
sudo apt-add-repository ppa:antonio.chiurazzi/ppa && sudo apt-get update
Install the Ubuntu Face Authentication / Face Recognition Library
sudo apt-get install pam-face-authentication
Tweak and Edit The System Now to add the face authentication module to GDM, Ubuntu's default login-manager:
sudo sed -i '1i auth sufficient pam_face_authentication.so enableX' /etc/pam.d/gdm
sudo sed -i '1i auth sufficient pam_face_authentication.so enableX' /etc/pam.d/gnome-screensaver
Depending on your webcam model/make you may need to install and add libv4l
to preload:
Create the file /etc/ld.so.preload
Paste in the path to the v4l1compat.so
file commonly found in /usr/lib/libv4l
Open "Face Trainer" (Application > Other), system will scan your face and add to database so that the system recognize your face while logi
Go to System > Administration > Users and Groups, change the password to Asked to login
Go to System > Administration > Login Screen, choose "Show the Screen for choosing who will log in", whis action will disable automatic login.
Done, you can logoff the system and test face authentication login in your ubuntu.
http://www.omgubuntu.co.uk/2010/09/login-to-ubuntu-using-your-face/
and
http://www.ubuntubuzz.com/2011/05/face-authentication-face-recognition.html
check these site you will get more info